Dispersion liquid, composition, sealing member, light emitting device, lighting tool, display device, and method for producing dispersion liquid

Abstract

A dispersion liquid including metal oxide particles surface-modified with a surface-modifying material, and a hydrophobic solvent, where said particles have a refractive index of 1.70 or higher and 2.00 or lower, the surface-modifying material includes a silane compound and a silicone compound, the silane compound includes a methyl group-containing silane compound, and if the dispersion liquid and methyl phenyl silicone are mixed so a total mass ratio of said particles and the surface-modifying material to methyl phenyl silicone is 7:93, thereby obtaining a cured product having a thickness of 1 mm, a scattering fraction at a wavelength of 450 nm of the cured product is 17% or more and 38% or less, and a value obtained by dividing the scattering fraction at a wavelength of 450 nm of the cured product by a scattering fraction at a wavelength of 600 nm of the cured product is 1.25 or higher.

1 . A dispersion liquid comprising:
 metal oxide particles surface-modified with a surface-modifying material; and   a hydrophobic solvent,   wherein the metal oxide particles have a refractive index of 1.70 or higher and 2.00 or lower,   the surface-modifying material includes a silane compound and a silicone compound,   the silane compound includes a methyl group-containing silane compound,   in a case where the dispersion liquid and methyl phenyl silicone are mixed such that a ratio of a total mass of the metal oxide particles and the surface-modifying material to a mass of methyl phenyl silicone is 7:93, thereby obtaining a cured product having a thickness of 1 mm,   a scattering fraction at a wavelength of 450 nm of the cured product is 17% or more and 38% or less, and   a value obtained by dividing the scattering fraction at the wavelength of 450 nm of the cured product by a scattering fraction at a wavelength of 600 nm of the cured product is 1.25 or higher.   
     
     
         2 . The dispersion liquid according to  claim 1 ,
 wherein the silane compound further includes a silane compound containing a hydrocarbon group having 2 to 5 carbon atoms.   
     
     
         3 . A composition which is a mixture of the dispersion liquid according to  claim 1  and a resin component. 
     
     
         4 . A sealing member which is a cured product of the composition according to  claim 3 . 
     
     
         5 . A light emitting device comprising:
 the sealing member according to claim  4 ; and   a light emitting element sealed by the sealing member.   
     
     
         6 . An illumination tool comprising:
 the light emitting device according to claim  5 .   
     
     
         7 . A display device comprising:
 the light emitting device according to claim  5 .   
     
     
         8 . A method for producing the dispersion liquid according to  claim 2 , the method comprising:
 a step B of mixing a silane compound and metal oxide particles to obtain a liquid mixture;   a step C of dispersing the metal oxide particles in the liquid mixture to obtain a first dispersion liquid in which the metal oxide particles are dispersed;   a step D of adding a hydrophobic solvent to the first dispersion liquid to obtain a second dispersion liquid; and   a step E of adding a silicone compound to the second dispersion liquid to obtain a third dispersion liquid,   wherein the metal oxide particles have a refractive index of 1.70 or higher and 2.00 or lower,   the silane compound includes a methyl group-containing silane compound and a silane compound containing a hydrocarbon group having 2 to 5 carbon atoms, in the step B, a content of the metal oxide particles in the liquid mixture is 10% by mass or more and 49% by mass or less, and a total content of the silane compound and the metal oxide particles in the liquid mixture is 65% by mass or more and 98% by mass or less, and   the step D is any of:   a step d1 of heating the first dispersion liquid and then adding the hydrophobic solvent to the first dispersion liquid at a rate at which the metal oxide particles are not agglomerated,   a step d2 of adding the hydrophobic solvent to the first dispersion liquid at a rate at which the metal oxide particles are not agglomerated, while heating the first dispersion liquid, or   a step d3 of adding the hydrophobic solvent to the first dispersion liquid at a rate at which the metal oxide particles are not agglomerated, and then heating the first dispersion liquid.   
     
     
         9 . A composition which is a mixture of the dispersion liquid according to  claim 2  and a resin component. 
     
     
         10 . A sealing member which is a cured product of the composition according to  claim 9 . 
     
     
         11 . A light emitting device comprising:
 the sealing member according to claim  10 ; and   a light emitting element sealed by the sealing member.   
     
     
         12 . An illumination tool comprising:
 the light emitting device according to claim  11 .   
     
     
         13 . A display device comprising:
 the light emitting device according to claim  11 .